General News

After 15 years of design and construction, the first proton-proton collisions were produced in the Large Hadron Collider (LHC) today. Collision observations were made in all four detectors located around the accelerator ring, including the CMS detector. The image attached to this article shows the flows of particles produced by one of the first collisions, as measured by CMS.

The University of Minnesota group is one of the leading groups on the CMS detector, with crucial development and leadership roles in the detectors designed to measure the energies of electrons, photons, and hadrons. Professor Roger Rusack, the project manager for the electomagnetic calorimeter, is present at CERN for the first collisions along with a number of graduate students and postdoctoral researchers. Professors Jeremiah Mans and Yuichi Kubota have been following the action from Minnesota. The atmosphere in the group office has been one of great excitement, with impromptu discussions of beam physics and the expected results of the first collisions breaking out among the graduate and undergraduate students as well as the professors.

The leader of the CMS collaboration, a joint effort of more than 2000 physicists and engineers, was overjoyed. “The events so far mark the start of the second half of this incredible voyage of discovery of the secrets of nature,” said CMS spokesperson Tejinder Virdee.

The Director-General of CERN, Rolf Heuer, hailed the achievement but reminded all of the challenges ahead: “It’s a great achievement to have come this far in so short a time. But we need to keep a sense of perspective – there’s still much to do before we can start the LHC physics program.”

The LHC was built to reproduce the conditions just after the Big Bang and to understand the nature of mass and perhaps produce dark matter. The first collisions have been achieved with beam energies of 450 GeV, a small fraction of the 7000 GeV design goal for the collider. Next on the schedule is an intense commissioning phase aimed at increasing the beam intensity and accelerating the beams. If all continues well, by Christmas the LHC should reach 1200 GeV (1.2 TeV) per beam, and have provided good quantities of collision data for the experiments’ calibrations and initial physics studies. Further updates will surely follow soon.